"a crucial enabling technology for electronic television. John Fleming invented the first radio tube, the diode, in 1904. Two years later, Robert von Lieben and Lee De Forest independently developed the amplifier tube, called the triode. In 1920, Albert Hull developed the magnetron which would eventually lead to the development of the microwave oven in 1946 by Percy Spencer. In 1934, the British military began to make strides toward radar (which also uses the magnetron) under the direction of Dr Wimperis, culminating in the operation of the first radar station at Bawdsey in August 1936. In 1941, Konrad Zuse presented"
"patent disputes leading up to World War I, it was only this ""loophole"" that allowed vacuum triodes to be manufactured at all, since none of De Forest's patents specifically mentioned this application). De Forest was granted a patent for his early two-electrode version of the Audion on November 13, 1906 (), but the ""triode"" (three electrode) version was patented in 1908 (). De Forest continued to claim that he developed the Audion independently from John Ambrose Fleming's earlier research on the thermionic valve (for which Fleming received Great Britain patent 24850 and the American Fleming valve patent ), and De"
"These were the first vacuum tube triodes. The name ""triode"" appeared later, when it became necessary to distinguish it from other kinds of vacuum tubes with more or fewer elements (e.g. diodes, tetrodes, pentodes, etc.). There were lengthy lawsuits between De Forest and von Lieben, and De Forest and the Marconi Company, who represented John Ambrose Fleming, the inventor of the diode. The discovery of the triode's amplifying ability in 1912 revolutionized electrical technology, creating the new field of ""electronics"", the technology of active (amplifying) electrical devices. The triode was immediately applied to many areas of communication. Triode ""continuous wave"""
"electronics revolution of the 20th century arguably began with the invention of the triode vacuum tube. The English physicist John Ambrose Fleming worked as an engineering consultant for firms including Edison Swan, Edison Telephone and the Marconi Company. In 1904, as a result of experiments conducted on Edison effect bulbs imported from the United States, he developed a device he called an ""oscillation valve"" (because it passes current in only one direction). The heated filament, was capable of thermionic emission of electrons that would flow to the ""plate"" (or ""anode"") when it was at a positive voltage with respect to"
"electronics devices such as radios and televisions until the 1970s, when transistors replaced them. Today, their main remaining use is in high-power RF amplifiers in radio transmitters and industrial RF heating devices. In recent years there has been a resurgence in demand for low power triodes due to renewed interest in tube-type audio systems by audiophiles who prefer the sound of tube-based electronics. The name ""triode"" was coined by British physicist William Eccles sometime around 1920, derived from the Greek τρίοδος, ""tríodos"", from ""tri-"" (three) and ""hodós"" (road, way), originally meaning the place where three roads meet. Before thermionic valves"
"was invented in 1904 by the English physicist John Ambrose Fleming. He developed a device he called an ""oscillation valve"" (because it passes current in only one direction). The heated filament, or cathode, was capable of thermionic emission of electrons that would flow to the ""plate"" (or ""anode"") when it was at a higher voltage. Electrons, however, could not pass in the reverse direction because the plate was not heated and thus not capable of thermionic emission of electrons. Later known as the Fleming valve, it could be used as a rectifier of alternating current and as a radio wave"
"Pentode A pentode is an electronic device having five active electrodes. The term most commonly applies to a three-grid amplifying vacuum tube (thermionic valve), which was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode consists of an evacuated glass envelope containing five electrodes in this order: a cathode heated by a filament, a control grid, a screen grid, a suppressor grid, and a plate (anode). The pentode (called a ""triple-grid amplifier"" in some early literature) was developed from the tetrode tube by the addition of a third grid, the suppressor grid. This served to prevent secondary"
"the second president of the Television Society. He was knighted in 1929, and died at his home in Sidmouth, Devon in 1945. His contributions to electronic communications and radar were of vital importance in winning World War II. Fleming was awarded the IRE Medal of Honor in 1933 for ""the conspicuous part he played in introducing physical and engineering principles into the radio art"". A note from eulogy at the Centenary celebration of the invention of the thermionic valve: In November 1905, he patented the ""Fleming Valve"" (). As a rectifying diode, and forerunner to the triode valve and many"
"detector. This greatly improved the crystal set which rectified the radio signal using an early solid-state diode based on a crystal and a so-called cat's whisker. However, what was still required was an amplifier. The triode (mercury-vapor filled with a control grid) was patented on March 4, 1906, by the Austrian Robert von Lieben independent from that, on October 25, 1906, Lee De Forest patented his three-element Audion. It wasn't put to practical use until 1912 when its amplifying ability became recognized by researchers. By about 1920, valve technology had matured to the point where radio broadcasting was quickly becoming"
"to give the sought-after ""sonic qualities"" of a triode power amplifier. A resistor may be included in series with the screen grid to avoid exceeding the screen grid's power or voltage rating, and to prevent local oscillation. Triode-connection is a useful option for audiophiles who wish to avoid the expense of 'true' power triodes. Pentode A pentode is an electronic device having five active electrodes. The term most commonly applies to a three-grid amplifying vacuum tube (thermionic valve), which was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode consists of an evacuated glass envelope containing five"
"History of the transistor A transistor is a semiconductor device with at least three terminals for connection to an electric circuit. The vacuum-tube triode, also called a (thermionic) valve, was the transistor's precursor, introduced in 1907. The first patent for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld published no research articles about his devices, and his work was ignored by industry. In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor. There is no direct evidence that these devices were built, but later work in the"
"Losev designed practical carborundum electroluminescent lights, but found no one interested in commercially producing these weak light sources. Losev died in World War 2. Due partly to the fact that his papers were published in Russian and German, and partly to his lack of reputation (his upper class birth barred him from a college education or career advancement in Soviet society, so he never held an official position higher than technician) his work is not well known in the West. In the 1920s, the amplifying triode vacuum tube, invented in 1907 by Lee De Forest, replaced earlier technology in both"
"Carver Mead and reported in 1966. History of the transistor A transistor is a semiconductor device with at least three terminals for connection to an electric circuit. The vacuum-tube triode, also called a (thermionic) valve, was the transistor's precursor, introduced in 1907. The first patent for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld published no research articles about his devices, and his work was ignored by industry. In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor. There is no direct evidence that these devices were"
"act as an electrostatic screen between the anode and the control grid (i.e. the first grid) in order to reduce the internal capacitance between control grid and anode. The first true screen-grid valve, with a screen grid designed for this purpose, was patented by Hiroshi Ando in 1919, and the first practical versions were built by N. H. Williams and Albert Hull at General Electric and Bernard Tellegen at Phillips in 1926. This type of tetrode was developed to correct deficiencies in the triode tube which became apparent when attempts were made to use triodes as small-signal radio-frequency amplifiers. In"
"Fleming valve The Fleming valve, also called the Fleming oscillation valve, was a thermionic valve or vacuum tube invented in 1904 by Englishman John Ambrose Fleming as a detector for early radio receivers used in electromagnetic wireless telegraphy. It was the first practical vacuum tube and the first thermionic diode, a vacuum tube whose purpose is to conduct current in one direction and block current flowing in the opposite direction. The thermionic diode was later widely used as a rectifier — a device which converts alternating current (AC) into direct current (DC) — in the power supplies of a wide"
"David Theodore Nelson Williamson David Theodore Nelson Williamson (also known as D.T.N. Williamson; 15 February 1923 – 10 May 1992) was a British electronics engineer, elected a Fellow of the Royal Society (F.R.S.) in 1968, most notable for a design of early high fidelity valve amplifier known as the Williamson amplifier that originally featured ""OSRAM"" brand valves (such as KT66 ""Kinkless"" Tetrode and L63 triode) made by the M. O. Valve Company, for which he had worked until 1946. The design was published in a series of articles in the influential British ""Wireless World"" magazine, beginning in May 1947. He"
"was bitter about his treatment. He honoured his agreement and didn't speak about it throughout Marconi's life, but after his death in 1937 said Marconi had been ""very ungenerous"". In 1904, working for the Marconi company to improve transatlantic radio reception, Fleming invented the two-electrode vacuum tube diode, which he called the oscillation valve, for which he received a patent on 16 November. It became known as the Fleming valve. The Supreme Court of the United States later invalidated the patent because of an improper disclaimer and, additionally, maintained the technology in the patent was known art when filed. This"
"efficiency as a result of reduced screen current. A further bonus was that third harmonic distortion was much reduced relative to a comparable pentode (Terman pp 198–9). Beam tetrode audio power output valves were introduced in 1937, and quickly replaced conventional pentodes in this application. Later developments produced beam power tubes which were capable of high-power output at frequencies extending into the UHF region. The beam tetrode was invented in Britain by two EMI engineers, Cabot Bull and Sidney Rodda, as an attempt to circumvent the power pentode, whose patent was owned by Philips. It was patented in 1933. Although"
"of his inventions were published in ""Scientific American"", but he is most noted for his 1891 treatise on factory management. In 1877 Tregoning filed his first patent request for an improved steam valve for pumping engines (see picture), and another patent in cooperation with Michael Hastings of Brooklyn, N.Y. for another improved pump valve. Both inventions were described the next year in the ""New Engineering Inventions"" section of ""Scientific American,"" August 1878, as follows. John Tregoning, of Brooklyn, N. Y., has patented an improved Steam Valve for pumping engines, which consists in a circumferentially grooved piston rod, which acts as"
"William Duddell William Du Bois Duddell (1 July 1872, Kensington, London – 4 November 1917, Wandsworth, London) was an English physicist and electrical engineer. His inventions include the moving coil oscillograph, as well as the thermo-ammeter and thermo-galvanometer. Duddell was born William Du Bois to Frances Kate Du Bois, who married George Duddell in 1881. At the age of four he constructed an automaton by combining a toy mouse with clockwork. Duddell was privately educated in England and France and rose quickly through the prestigious City & Guilds Schools via scholarships. He died at the age of 45. Prior to"
"1911 he was invited to deliver the Royal Institution Christmas Lecture on ""Signalling to a Distance"" and ""Modern Electricity"" respectively. William Duddell William Du Bois Duddell (1 July 1872, Kensington, London – 4 November 1917, Wandsworth, London) was an English physicist and electrical engineer. His inventions include the moving coil oscillograph, as well as the thermo-ammeter and thermo-galvanometer. Duddell was born William Du Bois to Frances Kate Du Bois, who married George Duddell in 1881. At the age of four he constructed an automaton by combining a toy mouse with clockwork. Duddell was privately educated in England and France and"
"stationary engine that won a gold medal at the 1878 Exposition Universelle in Paris. Egide Walschaerts Egide Walschaerts (21 January 1820 – 18 February 1901) was a Belgian mechanical engineer, best known as the inventor of the Walschaerts valve gear for use in steam locomotives. He was born in Mechelen, Belgium. In 1838 he was recognised as an excellent modeller, presenting his work at a local exhibition in Mechelen. Minister Rogier, who opened the exhibition, was so impressed that he arranged a place for Walschaerts at Liège University. In 1842 he joined the Belgian State Railways and two years later"
"Tigerstedt's innovation was to make the electrodes concentric cylinders with the cathode at the centre, thus greatly increasing the collection of emitted electrons at the anode. Irving Langmuir at the General Electric research laboratory (Schenectady, New York) had improved Wolfgang Gaede's high-vacuum diffusion pump and used it to settle the question of thermionic emission and conduction in a vacuum. Consequently, General Electric started producing hard vacuum triodes (which were branded Pliotrons) in 1915. Langmuir patented the hard vacuum triode, but De Forest and AT&T successfully asserted priority and invalidated the patent. Pliotrons were closely followed by the French type 'TM'"
"Lenard was awarded the Nobel Prize in Physics in 1905 for his work. Crookes tube A Crookes tube (also Crookes–Hittorf tube) is an early experimental electrical discharge tube, with partial vacuum, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were discovered. Developed from the earlier Geissler tube, the Crookes tube consists of a partially evacuated glass bulb of various shapes, with two metal electrodes, the cathode and the anode, one at either end. When a high voltage is applied between the electrodes, cathode rays (electrons) are projected in straight lines from"
"James Thompson Marshall James Thompson Marshall (1854, Glanford Brigg, Lincolnshire - 1931, Knaresborough, Yorkshire) was an English railway and mechanical engineer known for inventing the 'Marshall valve gear' for steam locomotive use. James Marshall began his engineering career at the Leeds-based Steam Plough Company, and later moved to the city's Boyne Engine Works. J. T. Marshall invented and patented several different valve gears but these should not be confused with the ""Marshall valve gear"" patented by Marshall, Sons & Co. in 1879. At least one of J. T. Marshall's valve gears was a rotary type and the only known application"
"James Thompson Marshall James Thompson Marshall (1854, Glanford Brigg, Lincolnshire - 1931, Knaresborough, Yorkshire) was an English railway and mechanical engineer known for inventing the 'Marshall valve gear' for steam locomotive use. James Marshall began his engineering career at the Leeds-based Steam Plough Company, and later moved to the city's Boyne Engine Works. J. T. Marshall invented and patented several different valve gears but these should not be confused with the ""Marshall valve gear"" patented by Marshall, Sons & Co. in 1879. At least one of J. T. Marshall's valve gears was a rotary type and the only known application"
"the Edison Effect could be used to detect radio waves. Fleming went on to develop the two-element vacuum tube known as the diode, which he patented on November 16, 1904. After further investivation while working for the Marconi Wireless Telegraph Co., Ltd., Fleming patented the Fleming Valve rectifier in 1904, resulting in the electron tube becoming the basis of modern electronics. William Joseph Hammer William Joseph Hammer (February 26, 1858 – March 24, 1934) was an American pioneer electrical engineer and aviator and he was president of the Edison Pioneers starting in 1908. He was a winner of the Elliott"
"beyond the unamplified limit of about 800 miles. The opening by Bell of the first transcontinental telephone line was celebrated 3 years later, on January 25, 1915. Other inventions made possible by the triode were television, public address systems, electric phonographs, and talking motion pictures. The triode served as the technological base from which later vacuum tubes developed, such as the tetrode (Walter Schottky, 1916) and pentode (Gilles Holst and Bernardus Dominicus Hubertus Tellegen, 1926), which remedied some of the shortcomings of the triode detailed below. The triode was very widely used in consumer electronics such as radios, televisions, and"
"John Ambrose Fleming Sir John Ambrose Fleming FRS (29 November 1849 – 18 April 1945), an English electrical engineer and physicist, invented the first thermionic valve or vacuum tube, designed the radio transmitter with which the first transatlantic radio transmission was made, and also established the right-hand rule used in physics. He was the eldest of seven children of James Fleming DD (died 1879), a Congregational minister, and his wife Mary Ann, at Lancaster, Lancashire, and baptised on 11 February 1850. A devout Christian, he once preached at St Martin-in-the-Fields in London on evidence for the resurrection. In 1932, he"
"patents seem to have gone at that time to the Soviet State Railway. Other sources speak of it being developed by Bulgarian railway engineers. Russian sources claim that the valve was invented in 1908 by a Moscow Sorting Station service technician I.Trofimov (or Trofimoff, thus the name), but the Russian Revolution and Civil War slowed adoption, so the design gradually spread on the word-of-mouth, and was patented only in the 1920s. The Trofimoff valve comprises the valve spindle, the piston valve heads slotted onto them and the two supporting plates (""Stützplatten""). When the engine is running under load the valve"
"The main advantages of the sleeve-valve engine are: Most of these advantages were evaluated and established during the 1920s by Roy Fedden and Harry Ricardo, possibly the sleeve valve engine's greatest advocate. He conceded that some of these advantages were significantly eroded as fuels improved up to and during World War II and as sodium-cooled exhaust valves were introduced in high-output aircraft engines. A number of disadvantages plagued the single sleeve valve: In 1901 Knight bought an air-cooled, single-cylinder three-wheeler whose noisy valves annoyed him. He believed that he could design a better engine and did so, inventing his double"
"invention is often considered to have been the beginning of electronics, for this was the first vacuum tube. Fleming's diode was used in radio receivers and radars for many decades afterwards, until it was superseded by solid state electronic technology more than 50 years later. In 1906, Lee De Forest of the US added a control ""grid"" to the valve to create an amplifying vacuum tube RF detector called the ""Audion"", leading Fleming to accuse him of infringing his patents. De Forest's tube developed into the triode the first electronic amplifier. The triode was vital in the creation of long-distance"
"Antoniadi in 1942, which was approved at the International Astronomical Union's 1948 General Assembly. Hanns Hörbiger Hanns Hörbiger (29 November 1860, in Atzgersdorf – 11 October 1931, in Mauer) was an Austrian engineer from Vienna with roots in Tyrol. He took part in the construction of the Budapest subway and in 1894 invented a new type of valve essential for compressors still in widespread use today. He is also remembered today for his pseudoscientific Welteislehre (""World Ice"") theory. Hanns Hörbiger was born in Atzgersdorf, a suburb of Liesing, Vienna and studied engineering at the local Technical College. In 1894 Hörbiger"